drivers/gpio/gpio.c

   1 /*
   2  * Copyright (c) 2016, ARM Limited and Contributors. All rights reserved.
   3  *
   4  * SPDX-License-Identifier: BSD-3-Clause
   5  *
   6  * GPIO -- General Purpose Input/Output
   7  *
   8  * Defines a simple and generic interface to access GPIO device.
   9  *
  10  */
  11
  12 #include <assert.h>
  13 #include <errno.h>
  14
  15 #include <drivers/gpio.h>
  16
  17 /*
  18  * The gpio implementation
  19  */
  20 static const gpio_ops_t *ops;
  21
  22 int gpio_get_direction(int gpio)
  23 {
  24         assert(ops);
  25         assert(ops->get_direction != 0);
  26         assert(gpio >= 0);
  27
  28         return ops->get_direction(gpio);
  29 }
  30
  31 void gpio_set_direction(int gpio, int direction)
  32 {
  33         assert(ops);
  34         assert(ops->set_direction != 0);
  35         assert((direction == GPIO_DIR_OUT) || (direction == GPIO_DIR_IN));
  36         assert(gpio >= 0);
  37
  38         ops->set_direction(gpio, direction);
  39 }
  40
  41 int gpio_get_value(int gpio)
  42 {
  43         assert(ops);
  44         assert(ops->get_value != 0);
  45         assert(gpio >= 0);
  46
  47         return ops->get_value(gpio);
  48 }
  49
  50 void gpio_set_value(int gpio, int value)
  51 {
  52         assert(ops);
  53         assert(ops->set_value != 0);
  54         assert((value == GPIO_LEVEL_LOW) || (value == GPIO_LEVEL_HIGH));
  55         assert(gpio >= 0);
  56
  57         ops->set_value(gpio, value);
  58 }
  59
  60 void gpio_set_pull(int gpio, int pull)
  61 {
  62         assert(ops);
  63         assert(ops->set_pull != 0);
  64         assert((pull == GPIO_PULL_NONE) || (pull == GPIO_PULL_UP) ||
  65                (pull == GPIO_PULL_DOWN));
  66         assert(gpio >= 0);
  67
  68         ops->set_pull(gpio, pull);
  69 }
  70
  71 int gpio_get_pull(int gpio)
  72 {
  73         assert(ops);
  74         assert(ops->get_pull != 0);
  75         assert(gpio >= 0);
  76
  77         return ops->get_pull(gpio);
  78 }
  79
  80 /*
  81  * Initialize the gpio. The fields in the provided gpio
  82  * ops pointer must be valid.
  83  */
  84 void gpio_init(const gpio_ops_t *ops_ptr)
  85 {
  86         assert(ops_ptr != 0  &&
  87                (ops_ptr->get_direction != 0) &&
  88                (ops_ptr->set_direction != 0) &&
  89                (ops_ptr->get_value != 0) &&
  90                (ops_ptr->set_value != 0));
  91
  92         ops = ops_ptr;
  93 }